Intraocular Pressure Changes Following Three "Head below the Heart" Postures in Yoga Practitioners - A Prospective Observational Study.

CONTEXT

Intraocular pressure (IOP) increases during "sirasasana" and may be a risk factor for the progression of glaucoma. Other "head below heart" asanas may also cause increase in IOP.

AIMS

To determine the change in IOP following three "head below the heart" postures-"meruasana", "viparithakarni," and "sarvangasana".

SETTINGS AND DESIGN

Prospective observational study conducted in a tertiary care hospital over 3 weeks.

MATERIALS AND METHODS

Willing, regular yoga practitioners recruited by purposive sampling performed "meruasana", "viparithakarni," and "sarvangasana" in random order according to a 3 × 3 periods cross over study design after baseline measurement of IOP, blood pressure (BP), and pulse rate. Each asana was held for 30 s. Within 15-30 s of completion of asana, IOP, BP, and pulse rate were recorded. There was an interval of 30 min between the asanas.

STATISTICAL ANALYSIS USED

Normality of data was tested using the Kolmogorov-Smirnov test. Repeated measures of ANOVA with Tukey-Kramer multiple comparisons was used to compare changes in IOP, BP, pulse rate following asana. ≤ 0.05 was accepted as statistically significant.

RESULTS

There were 33 participants with a mean age of 29.6 ± 10.5 years (95% confidence interval [CI]: 26.02, 33.18). The mean baseline IOP was 15.5 ± 3.4 mm Hg (95% CI: 14.34, 16.66) in the right eye and 16.7 ± 3.4 mm Hg (95% CI: 15.54, 17.86) in the left eye. IOP showed a significant reduction following each of the three asanas ( < 0.0001). However, neither pulse rate ( = 0.53) nor BP ( = 0.27) showed any change following the asanas.

CONCLUSIONS

"Meruasana," "viparithakarni," and "sarvangasana" when held for 30 s by healthy yoga practitioners resulted in post-asana drop in IOP with no significant change in pulse rate or BP.